<VV> Vapor lock issues SOLVED

[norman.witte at comcast.net]

I'm sure many of you recall my frustrating experiences with the Corsa turbo not starting after it had run for a little while.  I haven't had the problem for awhile and I wanted to share the fix.

The problem definitely was vapor lock.  The car was running extremely hot--indicating better than 450 deg at freeway speeds.  I made a number of changes that have reduced the operating temps considerably.  

First, I removed the lower shrouds.  This helped some, but in light of other changes I made, they will be reinstalled.

The second thing I did is to check the timing.  Although the car was running fine, the timing was retarded far too much.  I advanced the timing to the factory setting and this lowered temps quite a bit.  After I did this, the vapor lock problems went away, but temps still seemed awfully high.  As long as I kept speeds to about 65 mph the temp would stay just above 400, but if I accelerated beyond that it would climb rapidly.

Two other problems bothered me.  First was that fuel consumption was very high, and second was that under hard acceleration I could smell gas.  I knew that I was having gas pool in the air cleaner as the filter gasket material kept dissolving on the bottom outside edge.

I bought a fuel pressure regulator from Clarks and I installed it today.  I set it to "3" per Clarks' suggestion.  I then went out about half an hour ago and went for a freeway blast.  Ambient temps today are in the mid to upper 70s here, cooler than the week after the convention, but not cold.  I ran it up to  75--blew past a nice '60s VW bug that was crawling, probably because it had far too much positive rear camber and was handling like it was on ice--got off the freeway and drove home.  On the drive home at about 45 mph I noticed the temp gauge pegged at about 300 degrees.  Prior to installing the regulator I would have been running at about 400 degrees at that point.

So -- surprise surprise -- too much gas and timing too retarded makes motor run really hot.  I know now the fuel pump is working great.

Next issue is that the Safeguard isn't yet retarding, so I really don't dare trying to make boost.  I do get a little boost at high RPMs but it's not been the awe-inspiring experience I expected and it does knock at that point, which is something I obviously want to avoid.  So the first step is the Safeguard.  If I can get that sorted out, I should have a great running car.

Thanks to the many of you who helped me sort this out.

Norm